Studies on tandem ene/intramolecular diels-alder reactions

Giguere, R. J.; Namen, Andrew M.; Lopez, Blanca O.; Arepally, Aravind; Ramos, Danielle E.; Majetich, George; Defauw, Jean

doi:10.1016/s0040-4039(00)96911-9

Cited by 80 publications

(15 citation statements)

References 9 publications

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“…Thus, Giguere performed tandem ene/intramolecular DielsϪAlder reactions of 1,4-cyclohexadiene (4) with dimethyl acetylenedicarboxylate (5) in sealed tubes in commercial microwave ovens [12] (Scheme 2) and Rao reported on the cycloaddition of furan and cyclopentadiene derivatives with (1-chloro-1,2-difluorovinyl)phenylsulfone. [13] In both cases, the yields were greatly improved and reaction times reduced in relation to conventional heating.…”

Section: Reactions Under Pressurementioning

confidence: 99%

Cycloadditions under Microwave Irradiation Conditions: Methods and Applications

et al. 2000

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Microwave irradiation has been applied with success to cycloaddition reactions. The special characteristics of such irradiation entails the use of new methodologies, including equipment, glassware, solvents, and solid supports. All of these aspects are described in this review. Under classical heating conditions, these reactions usually require long reaction times, high temperatures, and/or Lewis acid catalysts, resulting in partial or total decomposition of sensitive compounds. This is a particularly significant problem in the synthesis of natural products. These problems have been conveniently overcome by the use of microwave irradiation. The short reaction time associated with microwave activation avoids decomposition of reagents and products, and prevents polymerization of the diene or dienophile. Heterocyclic compounds have been synthesized by cycloaddition reactions, or have been observed to react as dienes and dipoles under microwave irradiation conditions. Even those heterocyclic systems that are very reluctant to participate in cycloaddition reactions, such as pyrazoles, can be induced to react under microwave irradiation conditions. The application of this method to the chemistry of [60]fullerene has permitted derivatization of this system while avoiding the problems of polycycloaddition and cycloreversion. In most cases, spectacular accelerations and great improvements in yields and reaction conditions are observed. Finally, in some cases, changes in the chemo‐, regio‐, or stereoselectivity have been observed. These changes have been connected with the absolute hardness of the transition state, with the harder state being favored under microwave irradiation conditions. Microwave chemistry thus opens new possibilities for modifying the result of competitive reactions by considering the relative hardness of the transition states.

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Section: Reactions Under Pressurementioning

confidence: 99%

Cycloadditions under Microwave Irradiation Conditions: Methods and Applications

et al. 2000

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“…It has been reported that certain reactions such as Diels-Alder [15,16], ethenoid [17], Claisen reaction [18], Fischer cyclization [19], synthesis of heterocycles [20], hydrolysis of esters [21,22], phosphoanhydride [23] and adenosine triphosphate formation [24], rapid hydrogenation [25], deprotection of benzyl esters [26], deacetylation of diacetates [27], Graebe-Ullmann synthesis [28], oxazoline formation [29,30], Knoevengel condensation [31], and aromatic ether formation [32,33] could be facilitated by microwave irradiation. However, to the best of our knowledge, no such application has been devised for the previously described Mannich-type reaction.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of cyclic esters of N-toluenesulfonyl ?-aminophosphonic acid

Dai

Chen

1998

Heteroatom Chem.

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“…In 1986, Gedye and co-workers reported that hydrolysis reactions and some oxidations benefitted from microwave irradiation [96,97]. Soon afterwards, Giguere and Majetich reported their independent observations that Diels-Alder, Claisen, and ene reactions all demonstrated significant rate enhancements when compared to traditional heating methods [98][99][100][101]. A search of the terms "microwaves" and "synthesis" using SciFinder Scholar on May 23, 2013 produced a list of 64,739 references that have been published in the past twenty-seven years.…”

Section: Scheme 15 Comformational Analysis Of Triene Acetate 54mentioning

confidence: 99%

Diels-Alder Reactions of 12-Hydroxy-9(10®20)-5aH-abeo-abieta-1(10),8(9),12(13)-triene-11,14-dione

et al. 2013

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12-Hydroxy-9(10→20)-5aH-abeo-abieta-1(10),8(9),12(13)-triene-11,14-dione (quinone 2) served as the dienophile in numerous intermolecular Diels-Alder reactions. These cycloadditions were conducted either thermally (including microwave heating) or with Lewis acid activation. While most dienes reacted with quinone 2 in good chemical yield, others were incompatible under the experimental conditions used.

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Studies on tandem ene/intramolecular diels-alder reactions

Cited by 80 publications

References 9 publications

Cycloadditions under Microwave Irradiation Conditions: Methods and Applications

Cycloadditions under Microwave Irradiation Conditions: Methods and Applications

Synthesis of cyclic esters of N-toluenesulfonyl ?-aminophosphonic acid

Diels-Alder Reactions of 12-Hydroxy-9(10®20)-5aH-abeo-abieta-1(10),8(9),12(13)-triene-11,14-dione

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